BackgroundIn 1989–1991, a population-based cohort of every Missouri birth weighing < 1500 g was identified over a 16-month period. Infants born moderately low birth weight (MLBW, 1500–2499 g) and normal birth weight (NBW, ≥ 2500 g), were matched to < 1500 g infants by delivery date, race, maternal age, and residence. AimsTo compare outcomes of extremely low birth weight (ELBW, < 1000 g), very low birth weight (VLBW, 1000–1499 g), and MLBW, to NBW infants at age 10. Study designA population-based cohort and matched case-control study Outcome measuresA Child Health and Development Questionnaire developed for this study collected social, medical, educational and special services history. The Conners’ Parent Rating Scale-Revised was also completed by parents/caregivers. ResultsAs birth weight declined, the prevalence of adverse outcomes increased. Children in all LBW groups were more likely than NBW children to have problems in speech and language, vision, fine and gross motor tasks, illnesses, attention, school performance, and increased requirements for therapy and accommodation. Repetition of a grade was three times higher for MLBW children and over three times higher for the other LBW groups. ConclusionIn this statewide population-based study, controlling for child’s sex, mother’s age, race, residence, education, marital status, Medicaid assistance, and smoking or alcohol use during pregnancy, failed to eliminate the strong effect of decreasing birth weight. Problems were most frequent in ELBW, however, VLBW and MLBW also had many significantly greater problems than NBW children. All LBW groups of children experienced greater adverse health and developmental outcomes resulting in significant habilitation and educational challenges.